Wireless power receiver and control method thereof

ABSTRACT

A wireless power receiver according to an embodiment wirelessly receives power from a wireless power transmitter. The wireless power receiver includes a printed circuit board having a reception space in a predetermined area, a receiving coil disposed in the reception space of the printed circuit board for receiving power from the wireless power transmitter, and a short-range communication antenna disposed on the printed circuit board while surrounding the receiving coil.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/195,390, filed Jun. 28, 2016, entitled “Wireless Power Receiver andControl Method Thereof”, which is a continuation of U.S. applicationSer. No. 13/658,116, filed Oct. 23, 2012, now U.S. Pat. No. 9,461,364,issued on Oct. 4, 2016, entitled “Wireless Power Receiver and ControlMethod Thereof”, which claims the benefit under 35 U.S.C. § 119 ofKorean Patent Application No. 10-2011-0114721, filed Nov. 4, 2011,entitled “Apparatus for Receiving Wireless Power and Method forControlling Thereof”, all of which are incorporated herein by referencein their entirety.

BACKGROUND

The embodiment relates to a wireless power receiver and a control methodthereof.

A wireless power transmission or a wireless energy transfer refers to atechnology of wirelessly transferring electric energy to desireddevices. In the 1800's, an electric motor or a transformer employing theprinciple of electromagnetic induction has been extensively used andthen a method for transmitting electrical energy by irradiatingelectromagnetic waves, such as radio waves or lasers, has beensuggested. Actually, electrical toothbrushes or electrical razors, whichare frequently used in daily life, are charged based on the principle ofelectromagnetic induction. Until now, the long-distance transmissionusing the magnetic induction, the resonance and the short-wavelengthradio frequency has been used as the wireless energy transfer scheme.

Recently, among wireless power transmitting technologies, an energytransmitting scheme employing resonance has been widely used.

Since an electric signal generated between the wireless powertransmitter and the wireless power receiver is wirelessly transferredthrough coils in a wireless power transmitting system usingelectromagnetic induction, a user may easily charge electronicappliances such as a portable device.

However, due to the thickness of each of a receiving coil, a short-rangecommunication antenna and a printed circuit board constituting areceiving side, a size of an electronic appliance becomes larger and itis not easy to embed them in the electronic appliance. Specifically, thesize of the electronic appliance is increased corresponding to thethickness of the receiving coil, the short-range communication antennaand the printed circuit board.

Further, when an overcurrent flows through the short-range communicationmodule, it is difficult to effectively cope with the overcurrent.

Further, a magnetic field generated from the receiving coil exerts aninfluence on an inside of an electronic appliance, so that theelectronic appliance malfunctions.

SUMMARY

The embodiment provides a wireless power receiver with a minimizedthickness by suitably arranging a receiving coil, a short-rangecommunication antenna and a printed circuit board.

The embodiment provides a wireless power receiver with a reducedthickness by allowing a short-range communication antenna to be includedin a printed circuit board.

The embodiment provides a wireless power receiver which prevents anelectronic appliance from malfunctioning using a shielding unit.

The embodiment provides a wireless power receiver which breaks anovercurrent by using a protecting unit to protect a short-rangecommunication module.

A wireless power receiver according to the embodiment wirelesslyreceives power from a wireless power transmitter. The wireless powerreceiver includes: a printed circuit board having a reception space in apredetermined area; a receiving coil disposed in the reception space ofthe printed circuit board for receiving power from the wireless powertransmitter; and a short-range communication antenna disposed on theprinted circuit board while surrounding the receiving coil.

A wireless power receiver according to the embodiment wirelesslyreceives power from a wireless power transmitter. The wireless powerreceiver includes: a short-range communication antenna for performingshort-range communication; a receiving coil for wirelessly receivingpower from the wireless power transmitter; and a switch for changing aconducting state of the short-range communication antenna according to areception of the power, wherein the wireless power receiver opens orshorts the switch according to the reception of the power.

A method of controlling a wireless power receiver, which includes ashort-range communication antenna for communicating with an outside,according to the embodiment includes determining whether power isreceived from a transmitting coil through electromagnetic induction;opening a switch which changes a conducting state of the short-rangecommunication antenna when the power is received; identifying whether anamount of received power is equal to or greater than a threshold value;and shorting the switch when the amount of the received power is equalto or greater than the threshold value.

According to the embodiments, the thickness of the wireless powerreceiver can be minimized by suitably arranging the receiving coil, theshort-range communication antenna and the printed circuit board.

According to the embodiments, the wireless power receiver can beprevented from being broken by preventing an overcurrent from flowing inthe wireless power receiver and malfunction of the wireless powerreceiver can be prevented by shielding a magnetic field.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a wireless power transmission system accordingto the embodiment;

FIG. 2 is an equivalent circuit diagram of a transmitting coil accordingto the embodiment;

FIG. 3 is an equivalent circuit diagram of the wireless powertransmission system according to the embodiment;

FIG. 4 is a block diagram of a wireless power receiver according to theembodiment;

FIG. 5 is a view showing an example of a configuration of the wirelesspower receiver according to the embodiment;

FIG. 6 is a exploded perspective and sectional view illustrating thewireless power receiver according to the embodiment;

FIG. 7 is a sectional view showing an arrangement of elements of thewireless power receiver according to the embodiment;

FIG. 8 is a view illustrating a top surface and a bottom surface of thewireless power receiver according to the embodiment;

FIG. 9 is a view illustrating one example of attaching a shielding unitonto the wireless power receiver according to the embodiment;

FIG. 10 is a view illustrating one example of inserting the shieldingunit into the wireless power receiver according to the embodiment; and

FIG. 11 is a flowchart illustrating a control method of the wirelesspower receiver according to the embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, exemplary embodiments of the disclosure will be describedin detail so that those skilled in the art can easily comprehend thedisclosure.

FIG. 1 illustrates a wireless power transmission system according to anembodiment.

The power generated from a power source 100 is provided to a wirelesspower transmitter 200, such that the power is transferred byelectromagnetic induction to a wireless power receiver 300.

In detail, the power source 100 is an AC power source for supplying ACpower of a predetermined frequency.

The wireless power transmitter 200 includes a transmitting coil 210. Thetransmitting coil 210 is connected to the power source 100, such that anAC current flows through the transmitting coil 210. When the AC currentflows through the transmitting coil 210, an AC current is induced to thereceiving coil 310 physically apart from the transmitting coil 210 dueto electromagnetic induction, so that the AC power is transferred to thewireless power receiver 300.

Power may be transferred by electromagnetic induction between two LCcircuits which are impedance-matched with each other. The powertransmission through electromagnetic induction may enable highefficiency power transmission.

The wireless power receiver 300 may include a receiving coil 310, arectifier circuit 320 and a load 330. In the embodiment, the load 330may be not included in the wireless power receiver 300, but may beprovided separately. The power transmitted through the transmitting coil210 is received at the receiving coil 310 by electromagnetic induction.The power transferred to the receiving coil 310 is transferred throughthe rectifier circuit 320 to the load 330.

FIG. 2 is an equivalent circuit diagram of the transmitting coil 210according to the embodiment.

As shown in FIG. 2, the transmitting coil 210 may include an inductor L1and a capacitor C1, and form a circuit having a suitable inductancevalue and a suitable capacitance value. The capacitor C1 may be avariable capacitor. By controlling the variable capacitor, an impedancematching may be performed. Meanwhile, an equivalent circuit of thereceiving coil 320 may be equal to that depicted in FIG. 2.

FIG. 3 is an equivalent circuit diagram of the wireless powertransmitting system according to the embodiment.

As shown in FIG. 3, the transmitting coil 210 may include an inductor L1having a predetermined inductance value and a capacitor C1 having apredetermined capacitance value.

Further, as shown in FIG. 3, the receiving coil 310 may include aninductor L2 having a predetermined inductance value and a capacitor C2having a predetermined capacitance value. The rectifier circuit 320 mayinclude a diode D1 and a rectifying capacitor C3 such that the rectifiercircuit 320 converts AC power into DC power and outputs the DC power.

Although the load 330 is denoted as a DC power source, the load 330 maybe a battery or other devices requiring DC power.

Next, a wireless power receiver according to the embodiment will bedescribed with reference to FIGS. 4 to 10.

FIG. 4 is a block diagram of a wireless power receiver according to theembodiment, FIG. 5 is a view showing an example of a configuration ofthe wireless power receiver according to the embodiment, FIG. 6 is aexploded perspective and sectional view illustrating the wireless powerreceiver according to the embodiment, FIG. 7 is a sectional view showingan arrangement of elements of the wireless power receiver according tothe embodiment, FIG. 8 is a view illustrating a top surface and a bottomsurface of the wireless power receiver according to the embodiment, FIG.9 is a view illustrating one example of attaching a shielding unit ontothe wireless power receiver according to the embodiment, and FIG. 10 isa view illustrating one example of inserting the shielding unit into thewireless power receiver according to the embodiment.

First, referring to FIG. 4, the wireless power receiver 300 may includea receiving coil 310, a short-range communication antenna 340, a switch350, a protecting unit 360, a short-range communication module 370, ashielding unit 380, and a controller 390.

The wireless power receiver 300 according to the embodiment may beinstalled in a terminal or an electronic appliance requiring power, suchas a portable terminal, a laptop computer, and a mouse.

The receiving coil 310 receives power from the transmitting coil 210 ofthe wireless power transmitter 200 through electromagnetic induction.That is, if a magnetic field is generated as an AC current flows throughthe transmitting coil 210, a current is induced to the receiving coil310 by the generated magnetic field so that an AC current flowstherethrough.

In the embodiment, the receiving coil 310 may be disposed in a receptionspace of a printed circuit board 301.

The receiving coil 310 may be provided by winding a conducting wireserver times. In the embodiment, the receiving coil 310 may have aspiral shape, but the embodiment is not limited thereto.

The short-range communication antenna 340 may communicate with a readercapable of performing a short-range communication. The short-rangecommunication antenna 340 may perform a function of an antenna whichtransmits and receives information to and from the reader. In theembodiment, the short-range communication antenna 340 may be disposed atan outside of the receiving coil 310. In the embodiment, the receivingcoil 310 may be disposed in the reception space inside the printedcircuit board 301, and the short-range communication antenna 340 may bedisposed to surround the receiving coil 310 on the printed circuit board301.

The above configuration will be described in more detail with referenceto FIG. 6.

Referring to the exploded perspective view of the wireless powerreceiver 300 shown in FIG. 6(a), the wireless power receiver 300 mayinclude a case 302, the printed circuit board 301, the receiving coil310, the short-range communication antenna 340 and the shielding unit380. Here, the case 302 refers to a case of a portable terminal, but theembodiment is not limited thereto. The shielding unit 380 will bedescribed later.

Referring to FIG. 6(a), it may be identified that the receiving coil 310is disposed in the reception space A of the printed circuit board 301and the short-range communication antenna 340 is disposed on the printedcircuit board 301. That is, the receiving coil 310 may be disposed inthe reception space A provided inside the printed circuit board 301, andthe short-range communication antenna 340 may be disposed at an upperside of the printed circuit board 301 while surrounding the receptionspace A.

FIG. 6 (b) is a sectional view showing the arrangement of the elementsof the wireless power receiver 300 illustrated in FIG. 6(a).

In the embodiment, the printed circuit board 301, the receiving coil 310and the short-range communication antenna 340 may be inserted into thecase 302 through the injection molding. Further, as described above, theshort-range communication antenna 340 may be disposed at an outerperiphery on the printed circuit board 301 while surrounding thereceiving coil 310 placed in the reception space A.

Hereinafter, the arrangement among the receiving coil 310, theshort-range communication antenna 340 and the printed circuit board 301will be described in more detail with reference to FIGS. 7 and 8.

First, referring to FIG. 7, the printed circuit board 301 has thereception space A in a predetermined area thereof. In the embodiment,the predetermined area may include the central portion of the printedcircuit board 301. In the embodiment, the central portion of the printedcircuit board 301 may have the reception space having a polygonal shape,such as a rectangular shape and a circular shape.

The receiving coil 310 is disposed in the reception space A of theprinted circuit board 301, and receives power from the transmissioninduction coil 210 through electromagnetic induction. In the embodiment,the receiving coil 310 and the printed circuit board 301 may bemanufactured such that the thickness of the receiving coil 310 may beequal to that of the printed circuit board 301 or the thickness of thereceiving coil 310 may be less than that of the printed circuit board301. In this case, the increase of the thickness of the wireless powerreceiver 300 due to the thicknesses of the receiving coil 310 and theshort-range communication antenna 340 is prevented, so that the wirelesspower receiver 300 can be easily embedded in the case of the portableterminal.

In the embodiment, the receiving coil 310 may be manufactured to have ashape in match with a shape of the reception space A of the printedcircuit board 310. For example, when the shape of the reception space Aof the printed circuit board 310 is rectangular, the receiving coil 310or the conducting wire may be wound in a rectangular shape. When theshape of the reception space A of the printed circuit board 310 iscircular, the receiving coil 310 or the conducting wire may be wound ina circular shape. Thus, the receiving coil 310 or the conducting wiremay have various shapes.

The short-range communication antenna 340 may be included in the printedcircuit board 301 and may be configured to surround the receiving coil310. In the embodiment, the short-range communication antenna 340 may bemanufactured such that the short-range communication antenna 340 may beembedded in the printed circuit board 301, and may be configured tosurround the outer periphery of the receiving coil 310 having variousshapes such as a rectangular shape or a circular shape. In this case,the increase of the thickness of the wireless power receiver 300 due tothe thickness of the printed circuit board 301 and the short-rangecommunication antenna 340 can be prevented so that the wireless powerreceiver 300 can be easily installed in the case of the portableterminal.

The wireless power receiver 300 may further include a shielding unit 380for shielding a magnetic field generated by the receiving coil 310. Inthe embodiment, the shielding unit 380 may be disposed to cover an areaoccupied by the receiving coil 310. In the embodiment, the shieldingunit 380 may be disposed on the receiving coil 310 and the short-rangecommunication antenna 340 such that the shielding unit 380 may includethe area occupied by the receiving coil 310 and the short-rangecommunication antenna 340.

In the embodiment, the shielding unit 380 may have a reception space ina predetermined area thereof. A wireless charging circuit 375, which isplace on the top surface of the printed circuit board 301, may bedisposed in the reception space of the shielding unit 380. The wirelesscharging circuit 375 may include a rectifier circuit for converting ACpower into DC power, a capacitor for removing a noise signal, and a mainIC chip for performing the operation for the wireless power reception.

In the embodiment, the shielding unit 380 and the wireless chargingcircuit 375 may be manufactured such that the thickness of the shieldingunit 380 may be equal to that of the wireless charging circuit 375 orthe thickness of the shielding unit 380 may be less than that of thewireless charging circuit 375. In this case, the increase of thethickness of the wireless power receiver 300 due to the thicknesses ofthe shielding unit 380 and the wireless charging circuit 375 can beprevented, so that the wireless power receiver 300 can be easilyinstalled in the case of the portable terminal.

FIG. 8(a) is a view showing a bottom surface of the wireless powerreceiver according to the embodiment and FIG. 8(b) is a view showing atop surface of the wireless power receiver according to the embodiment.

FIG. 8(a) illustrates the arrangement of the printed circuit board 310,the receiving coil 310 and the short-range communication antenna 340according to the embodiment. The printed circuit board 301 has areception space A in the central area, and the receiving coil 310 havinga rectangular shape is disposed in the reception space A. Theshort-range communication antenna 340 is embedded in the printed circuitboard 301. In this case, the increase of the thickness of the wirelesspower receiver 300 due to the thickness of the printed circuit board 301and the short-range communication antenna 340 can be prevented, so thatthe wireless power receiver 300 can be easily installed in the case ofthe portable terminal.

Further, the receiving coil 310 and the printed circuit board 301 may bemanufactured such that the thickness of the receiving coil 310 may beequal to that of the printed circuit board 301 or the thickness of thereceiving coil 310 may be less than that of the printed circuit board301. In this case, the increase of the thickness of the wireless powerreceiver 300 due to the thickness of the receiving coil 310 and theprinted circuit board 301 can be prevented, so that the wireless powerreceiver 300 can be easily installed in the case of the portableterminal.

FIG. 8 (b) illustrates the arrangement of the wireless charging circuit375 and the shielding unit 380 according to the embodiment. Theshielding unit 380 may have a reception space in a predetermined areathereof, and the wireless charging circuit 375 may be disposed in thereception space of the shielding unit 380.

In the embodiment, the shielding unit 380 and the wireless chargingcircuit 375 may be manufactured such that the thickness of the wirelesscharging circuit 375 may be equal to that of the wireless chargingcircuit 375 or the thickness of the shielding unit 380 may be less thanthat of the wireless charging circuit 375. In this case, the increase ofthe thickness of the wireless power receiver 300 due to the thickness ofthe shielding unit 380 and the wireless charging circuit 375 can beprevented, so that the wireless power receiver 300 can be easilyinstalled in the case of the portable terminal.

Referring again to FIG. 4, although various technologies can be appliedto a short-range communication protocol used in the wirelesscommunication antenna 340 and a short-range are communication module 370which will be described below, NFC (Near Field Communication) may bepreferably used for the wireless communication antenna 340 and theshort-range communication module 370. The NFC is a technology forperforming wireless communication in a short-range through the bandwidthof 13.56 MHz.

The switch 350 is connected to the short-range communication antenna 340and receives an open or short signal from the controller 390 to bedescribed below such that the switch 350 may change a conducting stateof the short-range communication antenna.

If it is determined that the power is received from the transmittingcoil 320, the switch 350 may receive the open signal from the controller390 such that the switch 350 may break the current from flowing throughthe short-range communication antenna 340.

If the wireless power receiver 300 is charged with an amount of powerequal to or higher than a threshold value, the switch 350 may receivethe short signal from the controller 390 such that the switch 350 mayconduct the current through the short-range communication antenna 340,so the switch 350 may allow the short-range communication antenna 340 tobe operated.

The protecting unit 360 is operated when a current equal to or higherthan a threshold current value flows through the protecting unit 360,such that the protecting unit 360 may break the current equal to orhigher than the threshold current value from being transferred to theshort-range communication module 370.

In the embodiment, as shown in FIG. 5, the protecting unit 360 mayinclude at least one zener diode. The zener diode may allow only acurrent having a value equal to or less than a threshold current valueto flow through a circuit. The threshold current value may be variablyset and may be a limit value at which the short-range communicationmodule 370 may be normally operated.

When a current transferred to the short-range communication antenna 340has the threshold current value or above, the protecting unit 360changes the flowing direction or the flow of the current to prevent anovercurrent from flowing through the short-range communication module370.

Referring to FIG. 5, if the current flowing through the short-rangecommunication antenna 340 has the threshold current value or above, theprotecting unit 350 is operated. Referring to FIG. 5, when the currentflowing in the A-direction has the threshold current value or above, thecurrent having the threshold current value or above flows into the zenerdiode placed at an upper side of the protecting unit 350.

In a case that the current flowing in the B-direction has the thresholdcurrent value or above, the same procedure is performed.

An overcurrent having the threshold current value or above flows throughthe zener diode and is discharged as thermal energy. That is, theprotecting unit 360 may prevent the overcurrent from flowing through theshort-range communication module 370, so that damage of thecommunication module 370 may be prevented.

Referring again to FIG. 4, the short-range communication module 370 mayreceive a current through the short-range communication antenna 340.Although various types of communication technologies can be applied tothe short-range communication module 370, the NFC (Near FieldCommunication) protocol may be preferably used.

The shielding unit 380 may change a direction of the magnetic fieldgenerated from the receiving coil 310. The shielding unit 380 may absorbthe magnetic field generated from the receiving coil 310 and maydischarge the absorbed magnetic field as thermal energy.

That is, as the shielding unit 380 may change the direction of themagnetic field generated from the coil 310 or absorb and discharge themagnetic field as thermal energy, it is possible to prevent the magneticfield from exerting bad influence upon any other elements inside anelectronic appliance to which the wireless power receiver 300 isinstalled. That is, the shielding unit 380 can prevent the malfunctioncaused by the magnetic field applied to other elements.

The shielding unit 380 may include ferrite, but the embodiment is notlimited thereto.

The shielding unit 380 may be disposed at one side of the wireless powerreceiver 300.

Hereinafter, the arrangement of the shielding unit 380 on the wirelesspower receiver 300 will be described with reference to FIGS. 9 and 10.

First, referring to FIG. 9, after the short-range communication antenna340 has been disposed in the printed circuit board 301, the shieldingunit 380 may be attached to one side of the printed circuit board 301with an adhesive. The printed circuit board 301 comprises a plurality oflayers wherein each layer of the plurality of layers is spaced apartfrom adjacent layers. The shielding unit 380 is disposed under theshort-range communication antenna 340 or the receiving coil 310 (notshown in the FIG. 9).

Referring to FIG. 10, the printed circuit board 301 comprises aplurality of layers wherein each layer of the plurality of layers isspaced apart from adjacent layers, the short-range communication antenna340 or the receiving coil 310 (not shown in the FIG. 10) is disposed inthe printed circuit board 301. Moreover, the shielding unit 380 isdisposed in the printed circuit board 301. The shielding unit 380 isdisposed under the receiving coil 310 or the short-range communicationantenna 340. The receiving coil 310 (not shown in the FIG. 10). theshort-range communication antenna 340, and the shielding unit 380 aredisposed between the plurality of layers of the printed circuit board301. While the procedure of disposing the short-range communicationantenna 340 or receiving coil (310) (not shown in the FIG. 10) in theprinted circuit board 301 is being performed, the shielding unit 380 maybe inserted into the printed circuit board 301. That is, unlike FIG. 9,since the shielding unit 380 is disposed in the printed circuit board301, the procedure of disposing the shielding unit 380 may be includedin the procedure of disposing the short-range communication antenna 340without performing the procedure of disposing the shielding unit 380 atone side of the printed circuit board 301. That is, as described above,according to the embodiment shown in FIG. 8, when the shielding unit 380is inserted into the printed circuit board 301, the entire thickness ofthe wireless power receiver 300 may be reduced corresponding to thethickness of the adhesive 303. Thus, a separate procedure of attachingthe shielding unit 380 is not necessary, so the manufacturing processmay be simplified.

Referring again to FIG. 4, the controller 390 may control an entireoperation of the wireless power receiver 300.

The controller 390 may change an operating mode of the wireless powerreceiver 300 into a charging mode or a communication mode according to areception of the power. In the embodiment, the charging mode may be thatthe wireless power receiver 300 does not communicate with an outsidethrough the short-range communication module 370, but receives powerfrom the transmitting coil 210. The communication mode may be that thewireless power receiver 300 does not receive power from the transmittingcoil 210, but communicate with an outside through the short-rangecommunication module 370.

The controller 390 may change the conducting state of the short-rangecommunication antenna 340 by opening or shorting the switch 350. If acurrent is induced to the receiving coil 310 in the state that theswitch 350 is shorted, the controller 390 may open the switch 350 tochange the operating mode of the wireless power receiver 300 into thecharging mode. That is, if the controller 390 receives power from thetransmitting coil 210, the controller 390 opens the switch 350 toprevent the current from flowing through the short-range communicationantenna 340. In the state that the switch 350 is opened, if a current isnot induced to the receiving coil 310, the controller 390 may short theswitch 350 to change the operating mode of the wireless power receiver300 into the communication mode. That is, if the controller does notreceive power from the transmitting coil 210, the controller 390 mayshort the switch 350 to allow a current to conduct the short-rangecommunication antenna 340.

The controller 390 may sense the current flowing through the receivingcoil 310 for changing the conductive state of the short-rangecommunication antenna 340. In another embodiment, the wireless powerreceiver 300 may further include a separate current sensing unit (notshown) which can sense the current induced to the receiving coil 310 tosense the current flowing through the receiving coil 310.

The controller 390 may open or short the switch 350 according to anamount of power received at the wireless power receiver 300. This willbe described below with reference to FIG. 11.

FIG. 11 is a flowchart illustrating a control method of the wirelesspower receiver according to the embodiment.

Hereinafter, the control method of the wireless power receiver accordingto the embodiment will be described with reference to FIGS. 1 to 10.

In step S101, the controller 390 may determine whether the receivingcoil 310 receives power from the transmitting coil 210 throughelectromagnetic induction. In the embodiment, the wireless powerreceiver 300 may further include a detecting unit (not shown) todetermine whether power is received. A detecting coil may be used as thedetecting unit.

In step S103, if it is determined that the receiving coil 310 receivespower from the transmitting coil 210 through electromagnetic induction,the switch 350, which changes the conductive state of the short-rangecommunication antenna 340, may be opened. That is, the controller 390may transmit an open signal to the switch 350 to prevent the currentfrom flowing through the short-range communication antenna 340. In theembodiment, when it is determined that the receiving coil 310 receivespower from the transmitting coil 210 through electromagnetic induction,the wireless power receiver 300 may be in the charging mode. When thewireless power receiver 200 is operated in the charging mode to receivepower from the transmitting coil 310, the current flowing through theshort-range communication antenna must be shut off because the magneticfield generated during the charging mode may interfere with thecommunication between the short-range communication module 370 and theoutside.

Then, in step S105, the controller 390 may determine whether the amountof power received at the wireless power receiver 300 is more than thethreshold value. In the embodiment, although the threshold valuecorresponds to the state that the wireless power receiver 300 is chargedat 100%, the threshold value is not limited thereto and may be variouslyset by a user.

Then, in step S107, when the amount of power has the threshold value orabove, the controller 390 allows the switch to be shorted. In this case,the wireless power receiver 300 terminates the charging mode andoperates in the communication mode.

Then, in step S109, the controller 390 determines whether the currentflowing through the short-range communication antenna 340 is equal to orgreater than the threshold current value. In step S111, when the currentflowing through the short-range communication antenna 340 is equal to orgreater than the threshold current value, the current flowing directionmay be changed. In the embodiment, the threshold current value may meana limit value allowing the short-range communication to be operatednormally. In the embodiment, the threshold current value may bevariously set by a user. In the embodiment, the change of the currentflowing direction may be performed through the protecting unit 360. Inthe embodiment, the protecting unit 360 may be a zener diode. If thecurrent having the threshold current value or above flows, the zenerdiode performs the function of discharging the current as thermalenergy. In this case, the zener diode may prevent an overcurrent fromflowing through the short-range communication module 370, such thatdamage of the short-range communication module 370 may be prevented.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A wireless power receiver that wirelesslyreceives power from a wireless power transmitter, the wireless powerreceiver comprising: a board comprising a plurality of layers; awireless receiving coil disposed in the board; a short-rangecommunication coil disposed in the board; and a shielding unit disposedin the board, wherein the shielding unit is disposed on the wirelessreceiving coil and the short range communication coil, and wherein thewireless receiving coil, the short-range communication coil, and theshielding unit are disposed between the plurality of layers.
 2. Awireless power receiver of claim 1, wherein the plurality of playerscomprises a first layer, a second layer under the first layer, and athird layer under the second layer.
 3. A wireless power receiver ofclaim 2, wherein the shielding unit is disposed between the first layerand the second layer.
 4. A wireless power receiver of claim 3, whereinthe short-range communication coil is disposed between the second layerand the third layer.
 5. A wireless power receiver of claim 4, furthercomprising a separation distance between the second layer and the thirdlayer.
 6. A wireless power receiver of claim 5, wherein the separationdistance is smaller than a thickness of the short-range communicationcoil.
 7. A wireless power receiver of claim 3, wherein the wirelessreceiving coil is disposed between the second layer and the third layer.8. A wireless power receiver of claim 7, further comprising a separationdistance between the second layer and the third layer.
 9. A wirelesspower receiver of claim 8, wherein the separation distance is smallerthan a thickness of the wireless receiving coil.
 10. A wireless powerreceiver of claim 1, wherein the plurality of layers comprises a firstlayer, a second layer under the first layer, a third layer under thesecond layer, and a fourth layer under the third layer.
 11. A wirelesspower receiver of claim 10, wherein the shielding unit is disposedbetween the first layer and the second layer.
 12. A wireless powerreceiver of claim 11, wherein the wireless receiving coil comprises aplurality of layers.
 13. A wireless power receiver of claim 12, whereinthe wireless receiving coil is disposed between the second layer and thethird layer and between the third layer and the fourth layer.
 14. Awireless power receiver of claim 13, further comprising a separationdistance between the second layer and the third layer and between thethird layer and the fourth layer.
 15. A wireless power receiver of claim14, wherein the separation distance is smaller than a thickness of atleast one of the plurality of layers of the wireless receiving coil. 16.A wireless power receiver of claim 11, wherein the short-rangecommunication coil comprises a plurality of layers.
 17. A wireless powerreceiver of claim 16, wherein the short-range communication coil isdisposed between the second layer and the third layer and between thethird layer and the fourth layer.
 18. A wireless power receiver of claim17, further comprising a separation distance between the second layerand the third layer and between the third layer and the fourth layer.19. A wireless power receiver of claim 18, wherein the separationdistance is smaller than a thickness of at least one of the plurality oflayers of the short-range communication coil.
 20. A wireless powerreceiver of claim 1, wherein the wireless receiving coil comprises afirst wireless receiving coil and a second wireless receiving coil,wherein at least one of the plurality of layers is disposed between thefirst wireless receiving coil and the second wireless receiving coil.21. A wireless power receiver of claim 20, wherein a thickness of thefirst wireless receiving coil is thinner than a thickness of theshielding unit.
 22. A wireless power receiver of claim 21, wherein athickness of the first wireless receiving coil is thicker than athickness of at least one of the plurality of layers.
 23. A wirelesspower receiver of claim 1, wherein the short-range communication coilcomprises a first short-range communication coil and a secondshort-range communication coil, wherein at least one of the plurality oflayers is disposed between the first short-range communication coil andthe second short-range communication coil.
 24. A wireless power receiverof claim 23, wherein a thickness of the first short-range communicationcoil is thinner than a thickness of the shielding unit.
 25. A wirelesspower receiver of claim 24, wherein a thickness of the first short-rangecommunication coil is thicker than a thickness of at least one of theplurality of layers.
 26. A wireless power receiver of claim 1, whereinthe wireless receiving coil is surrounded by the short-rangecommunication coil.
 27. A wireless power receiver of claim 1, whereinthe shielding unit is arranged to correspond to an area occupied by thewireless power receiving coil and the short-range communication coil.28. A wireless power receiver of claim 1, wherein the shielding unitcomprises a ferrite.
 29. A wireless power receiver of claim 1, whereinthe board comprises a reception space.